<?php
Class Cnsubstr{
public static function str_cut($string, $length, $dot = '...') 
{ 
$strlen = strlen($string); 
if($strlen <= $length) return $string; 
$string = str_replace(array(' ', '&', '"', '\'', '“', '”', '—', '<', '>', '·', '…'), array(' ', '&', '"', "'", '“', '”', '—', '<', '>', '·', '…'), $string); 
$strcut = '';
if(strtolower(charset) == 'utf-8') 
{ 
$n = $tn = $noc = 0; 
while($n < $strlen) 
{ 
$t = ord($string[$n]); 
if($t == 9 || $t == 10 || (32 <= $t && $t <= 126)) { 
$tn = 1; $n++; $noc++; 
} elseif(194 <= $t && $t <= 223) { 
$tn = 2; $n += 2; $noc += 2; 
} elseif(224 <= $t && $t < 239) { 
$tn = 3; $n += 3; $noc += 2; 
} elseif(240 <= $t && $t <= 247) { 
$tn = 4; $n += 4; $noc += 2; 
} elseif(248 <= $t && $t <= 251) { 
$tn = 5; $n += 5; $noc += 2; 
} elseif($t == 252 || $t == 253) { 
$tn = 6; $n += 6; $noc += 2; 
} else { 
$n++; 
} 
if($noc >= $length) break; 
} 
if($noc > $length) $n -= $tn; 
$strcut = substr($string, 0, $n); 
} 
else 
{ 
$dotlen = strlen($dot); 
$maxi = $length - $dotlen - 1; 
for($i = 0; $i < $maxi; $i++) 
{ 
$strcut .= ord($string[$i]) > 127 ? $string[$i].$string[++$i] : $string[$i]; 
} 
} 
$strcut = str_replace(array('&','"',"'",'<', '>'), array('&','"','\'','<', '>'), $strcut); 
return $strcut.$dot; 
} 


//中文截取2，单字节截取模式 
//如果是request的内容，必须使用这个函数

public static function cn_substrr($str,$slen,$startdd=0) 
{ 
$str = cn_substr(stripslashes($str),$slen,$startdd); 
return addslashes($str); 
} 
//中文截取2，单字节截取模式 
public static function cn_substr($str,$slen,$startdd=0) 
{ 
global $cfg_soft_lang; 
if($cfg_soft_lang=='utf-8') 
{ 
return cn_substr_utf8($str,$slen,$startdd); 
} 
$restr = ''; 
$c = ''; 
$str_len = strlen($str); 
if($str_len < $startdd+1) 
{ 
return ''; 
} 
if($str_len < $startdd + $slen || $slen==0) 
{ 
$slen = $str_len - $startdd; 
} 
$enddd = $startdd + $slen - 1; 
for($i=0;$i<$str_len;$i++) 
{ 
if($startdd==0) 
{ 
$restr .= $c; 
} 
else if($i > $startdd) 
{ 
$restr .= $c; 
} 
if(ord($str[$i])>0x80) 
{ 
if($str_len>$i+1) 
{ 
$c = $str[$i].$str[$i+1]; 
} 
$i++; 
} 
else 
{ 
$c = $str[$i]; 
} 
if($i >= $enddd) 
{ 
if(strlen($restr)+strlen($c)>$slen) 
{ 
break; 
} 
else 
{ 
$restr .= $c; 
break; 
} 
} 
} 
return $restr; 
} 
//utf-8中文截取，单字节截取模式 
public static function cn_substr_utf8($str, $length, $start=0) 
{ 
if(strlen($str) < $start+1) 
{ 
return ''; 
} 
preg_match_all("/./su", $str, $ar); 
$str = ''; 
$tstr = ''; 
//为了兼容mysql教程4.1以下版本,与数据库教程varchar一致,这里使用按字节截取 
for($i=0; isset($ar[0][$i]); $i++) 
{ 
if(strlen($tstr) < $start) 
{ 
$tstr .= $ar[0][$i]; 
} 
else 
{ 
if(strlen($str) < $length + strlen($ar[0][$i]) ) 
{ 
$str .= $ar[0][$i]; 
} 
else 
{ 
break; 
} 
} 
} 
return $str.'...'; 
} 
}
?>